More than half the people in the United States hospitalized with H1N1, or swine flu, since Sept. 1 have been under the age of 25, the government reported today.

“This is still a younger person’s disease,” Dr. Anne Schuchat of the federal Centers for Disease Control and Prevention said during a press briefing today.

The CDC’s calculations are based on 4,958 lab-confirmed cases of H1N1 reported by 27 states between Sept. 1 and Oct. 10. Those numbers underestimate the extent of the disease, she said.

During the same time period those states reported 292 H1N1 deaths, about 25 percent of them people under 25, according to Schuchat.

H1N1 activity is now considered widespread across the country, including here in New York state.

The distribution of the new H1N1 vaccine is gradually increasing and should be widely available next month, Schuchat said. States have already ordered 10.8 million doses.

She also said communities should also see additional supplies next month of seasonal flu vaccine which has been getting scarce in many places.

The CDC is urging doctors to give antiviral medications like Tamiflu as soon as possible to people who have flu symptoms and are severely ill or at high risk of developing complications, especially pregnant women. Doctors should not wait for lab-confirmed test results before administering these medications, she said.